Carpal Tunnel Ultrasound and Injection
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Interventional radiologists are often asked to assist in achieving central venous access. This document outlines key decisions required in gaining assistance from an interventional radiologist in achieving the appropriate access for the clinical condition.
Venous access catheters can be tunnelled or non-tunnelled and are indicated for various conditions.
Peripherally-inserted central catheters and non-tunnelled central catheters are used for:
Tunnelled central catheters are used for:
In addition, these provide better cosmesis compared to the previously mentioned catheters, because both the catheter portion and the port are beneath the skin surface. Consequently, these catheters also require less maintenance and are less prone to becoming infected.
Long-term, active, systemic bacteraemia is an absolute contraindication.
Between 4% and 7% of venous access procedures have immediate complications. These are managed by the radiologist during or immediately after the procedure.
Infection, local or systemic (5-15% of patients). This may result in the catheter being removed, hospitalisation, antibiotics or all three.
Catheter blockage. This may occur from kinking of the catheter or blockage within the catheter (fibrin sheath or thrombosis). Definitive treatment usually involves the exchange of the existing catheter for a new catheter or fibrin sheath stripping.
Central vein thrombosis. The majority of these occur at the access site vein and are asymptomatic. However occasionally these may cause headache, head and neck swelling, arm swelling and/or arm pain, and pulmonary embolism. Treatment of symptomatic thrombosis is initially with anticoagulation. Severe cases may require thrombolysis and removal of the catheter.
Catheter fracture – the development of a crack or break in the catheter (less than 1% of cases)
Long term catheter malfunction – including an obstruction in the catheter or movement or dislodgement of the catheter (10-35% of cases). The latter usually requires catheter repositioning in the angiography suite.
Conventional intravenous access through the use of a cannula in a peripheral, superficial vein may be a viable short-term option, depending on the clinical situation. However, peripheral veins are prone to infusion phlebitis, which quickly leads to the depletion of accessible peripheral veins.
Alternative medical treatment may be considered, if relevant and appropriate, such as oral medications.
How to care for a venous access catheter:
Within the packaging for each catheter used, there is a detailed patient information booklet, which should be given to the patient or carer. Detailed step-by-step instructions are given for maintenance procedures.
Generally, implantable ports should be flushed monthly with normal saline.
Tunnelled and non-tunnelled catheters and PICC lines should be flushed daily with saline. If a valved cap is used on a catheter, flushing may be carried out weekly. After aspirating blood from the catheter, 20mL of saline should be used for flushing. After flushing with saline, heparin should be injected into the catheter or implantable port with a volume equal to the capacity of the catheter.
What to look out for:
Central venous thrombosis. This presents as arm or neck swelling, or may be life-threatening, presenting as pulmonary embolism and shortness of breath. The patient should be immediately referred to have an ultrasound or CT scan, preferably to the institution where the venous catheter was originally inserted, where appropriate and active management can be carried out.
Infection. This can occur at the catheter skin exit site, along the tunnel or within the blood stream, resulting in bacteraemia and sepsis. Skin infections can present with tenderness at the skin entry site, with or without erythema or exudate. Similarly, infection along the tunnel can present with tenderness along the tunnel, with or without overlying erythema or exudate and wound dehiscence.
Bacteraemia can present with fever. Infection at the skin exit site may be treated with antibiotics alone, but deeper infections will also require removal of the catheter.
Malfunctioning central venous catheter. A catheter may not be flushing or aspirating normally. It may be partially or completely blocked with a clot, cracked, kinked, encapsulated by a fibrin sheath or migrated. The patient should be referred back to the institution where the venous access was carried out for assessment and further management
Cardiovascular and Interventional Radiological Society of Europe:
Society of Interventional Radiology:
Page last modified on 21/9/2016.
RANZCR® is not aware that any person intends to act or rely upon the opinions, advices or information contained in this publication or of the manner in which it might be possible to do so. It issues no invitation to any person to act or rely upon such opinions, advices or information or any of them and it accepts no responsibility for any of them.
RANZCR® intends by this statement to exclude liability for any such opinions, advices or information. The content of this publication is not intended as a substitute for medical advice. It is designed to support, not replace, the relationship that exists between a patient and his/her doctor. Some of the tests and procedures included in this publication may not be available at all radiology providers.
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